Sand blast chamber door



p 1931. F. J. HULL SAND BLAST CHAMBER DOOR Filed Nov. 8, 1927 2 Sheets-Sheet l F. J. HULL Sept. 8, 1931.

SAND BLAST CHAMBER DOOR Filed Novv 8, 1927 2 Sheets-Sheet 2 Patented Sept. 8, 1931 UNITED STATESPATENT orsles FOSTER J. HULL, OF HAGERSTOWN, MARYIAND; ASSIGNOR T PANGBO'RN GORPOBEH- TION, 0F HAGER-STOWN- MARYLAND, A CORPORA'TION OF MHRYLAND SAND BLAST GHAMBER noon Application. filed November. 8, 1927. Serial No. 231,867.

The invention relates to sand blast. apparatus and particularly to a door structure for a sand blast chamber and the manner and" to resist the action of the abrasive. For this,

and for other reasons, while they are not massive they are necessarily so'heavy that.

when they are mounted'on the wall structure the tendency to distortion is dilhcult tovovercome and leakage due to imperfect fitting of the doors cannot be prevented. Also the peening action of the abrasive on the doors warps them and makes it necessary to adjust them from time to time to maintain the required fit.

ently of the wall structure of the sand blast The present invention provides a door mountin whereb the doorsare su' orted on thrust bearings which are, in turn, supported on the foundation or floor independchamber, the bearing member being conven' iently adjustable in all directions to. maintain the fit, and the door being adjustable upand down the shaft further being conveniently removable so that it may be straightened in: case of Warping due tothe peenmg action of the abrasive, or from other causes.

The bearing member or hinge shaft as mounted is preferably inclined inwardly 40 from the vertical toward the. chamber, im

parting to the door, or particularly the. cen ter of gravity thereof, a tendency to. swing upwardly as the door opens and downwardly. in closing, so that it is closed by gravity ob- Viating the necessity for springs or other.

closing means which would ordinarily be lo cated inside the door.

By the construction which is. the subject of the invention,.the bulk oftheload, due. to

the weight of the door and the strain of turning the doors,is removed from the'doorand placed on the foundation. The door also has a framework of steel angles or the equivalent, to which are bolted the shaft or hinge clam s. In this Way it is made possible to adjust the inclination of' the outer or swingingedge of the door by loosening one. of the clamps and forcing either the top or bottom of the door, thereby bringing the edge of the door in the proper vertical line to. make. the closure perfect. This overcomes the tendency of the doors to warp as aforesaid. Rubber sealing flapsare provided at all four edges.

The construction may be embodied in single or double door or a single or double panel door. With the double panel doors thefirst door mounted on the hinges ismade narrower at the bottom,the second pane'l'being'wider at the. bottom and the angular edges ofthepanels are connected by hinges. The angularit'y of the hinge joints gives the panel the closing tendency possessed by the hinged-door already outlined;

It is of interest to note thatthe mounting of'the doorson an inclined'shaft, as shown, which gives a gravity closing, also serves to raise. the doors:in. the open position whereby they are caused to clear any obstructions which maybe accidentally left on the floor.

In the accompanying drawings I have illustrated a sand blast chamber door emsupportat the base of the hinge shaft, the

same being. taken on theline 33 of Figure. 1, showing. the adjustment.

Figure 4' is a section on the line 44' of Figure 1 at. right angles to the section Figure 31 Figure 5 is a section on the line 55 of Figure 4 showing the thrust bearing at the base of the hinge shaft.

Figure 6 is a top plan View of the bearing support for the top bearing of the hinge shaft.

Figure 7 is a front elevation of a two panel door constructed in accordance with the invention.

Referring to the drawings by numerals, each of which is used to indicate the same or similar parts in the different figures, the construction shown comprises a sand blast chamber or enclosure 1 from which the atmos phere may be exhausted and the dust removed by way of suction or dust collector pipe 2. The chamber 1 is provided with a door opening 3 closed by means of sand blast chamber doors 4- and 5. These doors are preferably of sheet metal or any preferred material and to take the weight of the doors from the walls of the chamber, thereby preventing distortion of the chamber walls due to the weight of the doors and to make the doors easily adjustable to maintain a continuously perfect fit and tight closure of the sand blast chamber, they are mounted on hinge shafts 6 which are supported outside the chamber.

In the preferred construction shown, these shafts have at the bottom cone thrust bearings 7 supported on the thrust bearing base plate 8, which is supported on or in the concrete foundation or floor 9. The base plate 8 in the form of the invention shown rests directly on the base block 10 which, as shown, is set in the concrete foundation or floor 9.

To avoid the necessity for locks, springs and the like, to hold the doors in closed position, for it will be understood that they must be maintained closed during the operation of the blast, the shafts 6 are spaced outwardly at the base and inclined upwardly and inwardly toward the chamber wall which is preferably vertical, the shaft being aligned and supported laterally at the top by a bearing cap 11, the same being provided with a horizontally disposed base plate 12 adjustably secured to the top bearing bracket 14 by means of bolts 15 engaging slots 16, the bracket being adjustably secured to the top of the chamber by bolts 17 engaging slots 18 at right angles to the slots 16. The base plate 8 of the bottom bearing is adjustably secured to the block 10 by means of bolts 20 seated at their heads 22 in the block 10 and extending upwardly through slots 21 in the base plates. The heads 22 of the bolts 20 are mounted in dove-tailed slots 2 1 in the block 10 at right angles to the slots 21 in the base. By this arrangement the base 8 with the bottom thrust bearing 7 may be adjusted toward and from the adjacent wall of the chamber 1 or parallel thereto or in any intermediate direction.

In order to impart to the doors a perma nent tendency to move toward closed position the hinge shafts 6 are inclined, as aforesaid, from a point at the base spaced outwardly from the wall of the chamber which is assumed to be vertical inwardly and upwardly to the top bearing 11. The aXis being thus inclined, the center of gravity of the door moves upwardly as the door is swung out wardly from closed position to right angular position, but from this position, i. e., from ninety degrees to one hundred and eighty degrees, if the door swings backward toward full open position at one hundred and eighty degrees to the closed position it moves downwardly from the ninety degree position so that the tendency to close is eliminated and substituted by a tendency to swing open. To fix and determine the full open position a stop arm 20 may be soured to the hinge shaft (5. the stop being adjustable and shown as located at or nearly at right angles to the adjacent wall 27 of the chamber in the closed position of the door. By contact of the outer end of this arm with the outside of the chamber wall the swing of the door is limited.

The door is mounted on and secured to the shaft 6 by means of binge clamps 2S and 29 which are formed in two halves in the nature of a split collar, encircling the shaft and secured by bolts 30 in, clamping position. Each side clamp 28, 29 has a projecting flange or arm 31 integral with one-half of said collar which is bolted to the door framework, or stiffeners 32, each of which is shown in the form of two angles, each having one web secured to the door, the other webs being placed in close contact each with the other in a position at right angles to the door. These stiifeners 32 are secured to the door by belts or rivets 33 or in any suitable manner. The bolts 30 provide for the removal of the door at the top or bottom or both at any time and also by loosening these bolts the door may be adjusted up and down, the shaft 6, as aforesaid, being adjusted either along the wall. 2'? or toward and from the same at the top and bottom by means of the adjustments 15, 16, 17, 18 and 20, 21, 22, 2 1.

In case the door is warped by the action of the abrasive or otherwise, one or both of the hinges or clamps may be loosened and the door may be forced either at the top or bottom and reclamped, bringing the corresponding ends of the door into the proper vertical alignment to effect a tight closure. Such a provision is essential on account of the tendency to warp and twist due to the peening action of the abrasive. It will also be noted, see Figures 1 and 2, that the bolts 30 whereby the hinges are attached to the door are spaced inwardly from the edge of the door adjacent the hinges and that said edge of the door, see Figure 2, is spaced well away from the shaft. This arrangement leaves all four edges of the door free for adjustment to the opening by deflection of the edges as described to overcome warping and the like and to cause the door to fit tightly the opening at all times.

As a means for effecting a tight closure of the door the top, bottom and vertical edges of the doors are provided with outwardly projecting rubber flaps 35 which are pressed and flattened in the closed. position of the door at the bottom against the floor and at the top against the outwardly projecting web 36. At the meeting edges of the door the flaps may overlap and contact with each other and at the edges adjacent the hinges they lie fiat against the wall of the chamber.

In the form of the invention shown, the hinge shaft 6 is tubular and the cone bearing 7 at the bottom is formed by the insertion in the bottom end of the shaft of a plug 39 shouldered intermediately at 40 to engage the lower end of the pipe, the projecting portion of the plug being flared outwardly in the frustrum of a cone 41 which is cupped providing a conical bearing opening 42 extending upwardly into the bottom of the plug, the upper end of the conical opening being preferably rounded at 43. This conical bearing opening is engaged by a conical pin 44: likewise rounded at its upper end at 45. This pin 414: projects upwardly from the bottom bearing base plate 8 providing in connection with the plug member 39 a conical thrust bearing to support the hinge shaft.

In Figure 7 I have shown a double panel door for sand blast chamber or room constructed in accordance with the features of my invention as already outlined. The hinge shaft 60 at the left with hinge clamps 61, 62 and angle iron stiffeners 63 to which the hinge clamps are secured, are all preferably similar to the corresponding members of the structure already described. To give the gravity closing effect as to the outer panel 65 the inner panel 66 is made narrower at the bottom than at the top, giving an inclined outer or swinging edge of the inner panel at 67 and the outer panel 65 is made wider at the bottom than at the top giving a rectangular outline to the complete door and producing a hinged edge 68 parallel to and adapted to contact with the outer edge 67 of the inner panel. The outer panel 65 is mounted to swing on, and relatively to the inner panel 66 by means of hinges 69, one member of each of which is secured to the corresponding stiffener 63 of the inner panel, the other member of each hinge being secured to the corresponding stiffener 70 of'the outer panel 65. The angularity of the hinged joint between the panels will cause the second or outer panel to close by gravity when released from restraint.

To open a door of this type the second or outer panel will be turned back and latched against the first panel, any suitable type of latch as that shown at 71, 72, Figure 7, being utilized for this purpose. Then the two panels can be rotated about the shaft 60 as in the case of a single door, the weight of the door, i. e., the force of gravity opposing the operation until the door reaches central position, when it may be swung backward by gravity to a position at substantially one hundred and eighty degrees from its normal closed position.

It is of interest to note that in the opening action, the door being raised to give a gravity closing, the doors pass over without touching any slight obstructions, as bricks 75, which may be on the floor in front of the door opening.

I have thus'described specifically and in detail a door structure and mounting particularly adapted for use in connection with sand blast chambers or the like, in order that the nature and operation and manner of using the same may be clearly understood, however, the specific terms herein are used descriptively rather than in a limiting sense, the scope of the invention being defined in the claims.

WVhat I claim as new and desire to secure by Letters Patent is:

l. The combination with a sand blast chamber having a door opening, of a door for the same, a hinge shaft for the door, a

bearing supporting the same at the bottom independently of the chamber structure, a bearing for the shaft at the top, a door having its outer swinging edge inclined downwardly and inwardly toward the shaft in closed position, a panel mounted on the swinging edge of the door, hinges connecting the said panel to the door, the panel being formed with its hinged edge inclined downwardly and inwardly toward the hinge shaft, whereby the panel tends to swing about the door to closed position.

2. The combination with a sand blast chamber having a door opening and a door assembly comprising a swinging sheet metal door to close the opening, of a shaft for each door, the said shaft having a cone hearing at the bottom with the inside conical member of said bearing upwardly disposed toimpose the weight of the door on the floor or foundation, means for adjusting this member in all horizontal directions, each door having clamps securing it to the shaft so that it may be adjusted along the shaft, providing means whereby the doors when warped by the peening action of the abrasive may be quickly and easily restored to position in which they close accurately and form a seal at all edges of the opening without removing any part of the assembly.

Signed by me at Hagerstown, Maryland, this 19th day of September, 1927.

FOSTER J. HULL. 

